Quantity 

Size  American Size 4.5 = European 1.5 American Size 5 = European 2 American Size 5.5 = European 2.5 American Size 6 = European 3 American Size 6.5 = European 3.5 American Size 7 = European 4 American Size 7.5 = European 4.5 American Size 8 = European 5 American Size 8.5 = European 5.5 American Size 9 = European 6 American Size 9.5 = European 6.5 American Size 10 = European 7 American Size 10.5 = European 7.5 American Size 11 = European 8 American Size 11.5 = European 8.5 American Size 12 = European 9